[Datasets] [Docs] Fix bug in Datasets locality-aware splitting example (#21937)
[Datasets] [Docs] Fix bug in Datasets locality-aware splitting example (#21937)

Fixes bug in Datasets locality-aware splitting example.
ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray,ray-project/ray